In this paper, we describe PAG (Prototyping with Attribute Grammars), a framework for building Prolog prototypes from specifications based on attribute grammars, which we have developed for supporting rapid prototyping activities in an introductory course on language processors. This framework works for general noncircular attribute grammars with arbitrary underlying context-free grammars, includes a specification language embedded in Prolog that strongly resembles the attribute grammar notations explained in the course cited, and lets students produce comprehensible prototypes from their specifications in a straightforward way. Key words: attribute grammars, language prototyping framework, education in language processors, Prolog